反硝化微生物燃料电池的基础研究

摘要

The influence of dissolved oxygen in cathode and external resistance on the performance of electricity generation and pollutant removal of microbial fuel cell (MFC) were investigated after successful start-up of a double-chamber denitrifying MFC. The results revealed that, with sodium acetate as electron donor and sodium nitrate as electron acceptor under the ambient temperature of 25 ℃, the denitrifying MFC was started successfully in 42 days through continuous feeding followed by batch feeding. The oxygen and nitrate could serve as electron acceptor simultaneously when oxygen existed in the influent of cathode. In the lower range of current density, oxygen was the main electron acceptor with a maximum power density of 26.0W/M3nc; as the current density increased to a certain extent, nitrate became the main electron acceptor gradually with a maximum power density of 20.9W/M3nc. The external resistance had little effect on COD removal and denitrifying degree, and the COD removal loading maintained at about 1.2kg/(M3nc·d) with the effluent concentration of NO2-N below 0.05mg/L; but decreasing the external resistance resulted in improvement of nitrogen removal performance in cathode, and the NO3-N removal loading reached to 0.11 lkg/(M3nc·d) when the external resistance was set at 5Ω.%在启动双室型反硝化微生物燃料电池的基础上,研究了阴极溶解氧及外电阻对其产电性能和污染物去除效果的影响.结果表明,以乙酸钠为阳极电子供体,硝酸钠为阴极电子受体,在25℃的环境温度下,采用先间歇后连续培养的方式,42d内成功启动了反硝化微生物燃料电池.在阴极进水含氧的情况下,氧和硝酸盐可共同用作阴极电子受体.在较小电流密度区域内,氧是阴极的主要电子受体,相应的最大功率密度为26.0W/m3NC;电流密度增加到一定程度后,硝酸盐逐步变为阴极的主要电子受体,相应的最大功率密度为20.9W/m3NC.外阻变化对COD去除及反硝化程度影响较小,阳极COD去除负荷维持在1.2kg/(m3NC·d)左右,出水NO 2-N保持在0.05mg/L以下；但外阻减小有利于提高阴极脱氮效果,外阻为5Ω时NO3-N去除负荷达0.111 kg/(m3NC·d).